This invention relates to tape cassette and, more particularly, to a device for preventing despooling of tape from reels of a video cassette when the tape cassette is not received by a tape player/recorder.
A conventional tape cassette has a relatively flat, substantially rectangular configuration, formed of a suitable plastic. The cassette includes a base and cover, each having side walls. Tape reels are usually suitably located in side-by-side relation within the cassette so as to be freely rotatable, and a magnetic tape is would on the tape reels. A reel leaf spring is attached to the cassette cover to normally bias the tape reels in the direction of the base.
Tape reel locks have been used to prevent unwanted "despooling" of the tape during shipping, handling, etc. However, such locks must disengage and allow rotation of the reels when the cassette is received by the tape player/recorder for operation.
More particularly, when tape is wound on the reels during manufacturing, air is caught between the windings. During subsequent shipment, handling, etc., even though the reels are locked, despooling can occur, i.e., the air is squeezed out, the tape becomes more tautly wound on the reels, and excess tape accumulates between the reels at the open end of the cassette. Despooled, exposed tape can, of course, be easily damaged.
The industry has almost uniformly adopted a multipiece reel lock, such as shown and described in U.S. Pat. Nos. 4,447,020 or 4,232,840. Such multipiece reel locks include a separate actuator/retractor, a pair of separate movable arms for respectively locking the reels, and a separate spring for biasing the arms toward the reels. These reel locks are assembled in between the tape reels in walls/receptacles formed in the cassette base and are actuated by a pin of the player that protrudes through the base.
Of course, such a multipiece lock is rather expensive to produce and assemble. Further, due to the number of parts and the fabrication requirements for each part, production yields cannot be maximized
Assignee's currently pending U.S. patent application Ser. No. 389,906, entitled "Video Cassette Integral Actuator/Reel Lock/Spring" provides an improved one-piece reel lock, significantly decreasing manufacturing and assembly costs, and reliably locking the reels. Notwithstanding this advance, the art still is in need of a reel lock which needs no assembly and requires no moving parts, to further simplify structure, improve quality and reliability and minimize costs.